There are a number of conventional practices in the field of film and video editing which have evolved over time to assist the viewer of a video or audiovisual presentation in understanding the activity portrayed from the limited viewpoints of a finite number of camera positions. One such convention, that is particularly applicable to football or similar games where the progress of the action in a particular direction indicates an advantage to a particular team or participant, is that the direction of movement of the action should be portrayed consistently. It is thus common practice for all the cameras contributing to the broadcast of a football match to be situated on the same side of the pitch so that the viewer can instinctively associate horizontal movement towards a particular side of the image with an advantage to a particular team.
This conventional limitation can deny the viewer some information which would otherwise aid the understanding of the game, for example because some important action is masked by players situated between the camera and some particular critical action. Thus situations arise where defying the convention provides more information for the viewer, and therefore a view from an ‘unexpected’ direction is used. In such cases it is usual practice to add a caption, or audio commentary, to the relevant image so that the viewer can relate the new direction of view to previous views. This need for an additional caption or commentary is an inconvenient limitation.
One simple way of intuitively conveying to the viewer the fact that the viewpoint has been changed, and thus avoiding the need for an additional caption or commentary, is for the camera to move physically from one viewpoint to another while its output is presented to the viewer. This immediately emphasises that the viewpoint has changed and helps to convey the spatial relationship between the previous and current views of the scene. This procedure is usually impractical, except in the case of hand-held, portable cameras, and even then the time to move the camera will often be excessive, and the camera may not be able to be moved in a smooth and visually pleasing manner.